Lecture (November 18th): Basics of iOS Development

iPHONE + iPAD:SUDDENLYSOMETHING ELSE∞ · NOVEMBER 18th 2010 · HCI · POLIMI

venerdì 19 novembre 2010

THE FUTUREOH MY GOD THE FUTURE


PROGETTO

DATA STATO1987-2001 SCIENCE FICTION

TRICORDER + D-PADSTAR TREK TNG · DS9 · VOYAGER


FUTUREOH MY GOD THE FUTURE AND IT IS HERE

PRESENT


1. It’s full of stars(THE FUTURE IS HERE THE FUTURE IS HERE)


2. It’s where users are!

“THE IPHONE HAS BEEN ABLE TO MAINTAIN OVER 100% Y/Y GROWTH ON AVERAGE.”WWW.ASYMCO.COM


http://www.asymco.com

http://www.asymco.com

… (maybe because it’s the most usable?)


3. €€€€€€€€€€€€€€€€€€€(case study: me.)


APPLE IPHONE 3G AD: “SHARE”.HTTP://WWW.YOUTUBE.COM/WATCH?V=0CIPNTUVX0C


http://www.youtube.com/watch?v=0ciPntuvX0c

http://www.youtube.com/watch?v=0ciPntuvX0c

> 2,2 million free d/l> 95,000 paid downloads


È STATO UN POMERIGGIO DI FINE ESTATESTAVO CAMMINANDO PER LE VIE DEL CENTRO MILANESE (IN CUI PIACE MOLTO PERDERMI) ED ERO IN ZONA BRERA QUANDO SENTO SQUILLARE IL MIO CELLULARESECCATO LO TIRO FUORI, MA UNO SGUARDO ALLO SCHERMO ACCENDE LA MIA CURIOSITÀ. “+44” DICE LO SCHERMO (NON RICORDAVO AL MOMENTO MA QUELLO ERA IL PREFISSO INTERNAZIONALE DEL REGNO UNITO).ALL’ALTRO CAPO UNA VOCE ITALIANA MI FA “CIAO, SONO NONPOSSODIRLO DI APPLE, CHIAMO DA LONDRA.VORRESTI METTERE LA TUA APP NEL NOSTRO SPOT?”


YOU, MAKING APPS.(Let’s talk about it.)


Design.


The iPhoneIS A BUNCH OF SENSORS IN YOUR POCKET WITH A SCREEN.


PLAYING MAKE-BELIEVEEXCEPT IT WORKS FOR REAL


IBOOKS BY APPLE.


OCARINA BY SMULE.HTTP://WWW.YOUTUBE.COM/WATCH?V=RHCJQ7EAJJA


http://www.youtube.com/watch?v=RhCJq7EAJJA

http://www.youtube.com/watch?v=RhCJq7EAJJA

The iPhoneIS DIFFERENT FROM A DESKTOP COMPUTER BLUH BLUH BLUH


Desktop differences

Quick use. (Pick it up, use it, back in the pocket.)

Imprecise input, bad (best-of-breed) keyboard.

Made for touching: direct manipulation.

Point to pick!


The iPhoneIS DIFFERENT FROM ITS COMPETITORS


Differences with other phones/OSes (I)

All OS tries to rate good-if-not-best.

Most needed stuff built in.

(Many other factors, but few directly affecting us.)


Differences with other phones/OSes (II)

One thing at a time: discrete apps.

Consistency broken very carefully.

RELIABLE!


iOS≈ Mac OS X (but different)


iOS

No filesystem

Instead, discrete tasks in apps!

Built atop responsiveness

Animation everywhere.

No virtual memory (writing)

Apps must not make the OS go out of memory!


Apps

Isolated!

Can communicate (URLs, open files, pasteboard [copy/paste])

User always in control.

If user presses Home, YOU QUIT.


Tools.NOT CHEAP!


REQUIRED STUFF »


PLATFORM

DATE STATUSNOVEMBER 15 NEW MACS EVERY 3-6 MONTHS

A MAC€999+


TOOLS

DATE STATUSNOVEMBER 15 IN FLUX

XCODEXCODE TOOLS + IOS SDK 4


http://developer.apple.com/iosTOOLS ARE FREE · INCLUDES SIMULATOR


http://developer.apple.com/ios


OPTIONAL STUFF (at least at the time you start) »


TESTDEVICE

DATE STATUSNOVEMBER 15 EXPENSIVE

IPHONE€539+ (ACTUALLY OPTIONAL)


TESTDEVICE

DATE STATUSNOVEMBER 15 MUCH CHEAPER!

IPOD TOUCH€239+ (ACTUALLY OPTIONAL · WI-FI ONLY)


http://developer.apple.com/iosDEVICE DEBUG + DEPLOY: € 79/year




And now ACTUAL DEVELOPMENT STUFF.


Objective-C.C + OBJECTS.


float f = 1.23;int x = fabs(f);

PURE C.

float f = 1.23;int x = fabs(f);

OBJECTIVE-C.


[calculator add:1 to:2 and:3];// method == “-add:to:and:”// arguments == 1,2,3


-(void) add:(int)a to:(int)b and:(int)c;


NSString* x = …;NSString* y = [x substringToIndex:10];


id x = …;id y = [x substringToIndex:10];


NSArray* a = …;[a addObject:@“12345”];


NSArray* a = …;[a performSelector:@selector

(addObject:) withObject:@“1234”];


VIEW CONTROLLERS


VIEWSmake up what’s onscreen

VIEW CONTROLLERSmake up the LOGICAL structure of your app.

NAVIGATION

ALL SONGS » FAVORITES »

EDIT » SONG PICKER


UIAPPLICATION

the app’s DELEGATE

WINDOW

views for 1

VIEW CTL 1 VIEW CTL 2

views for 2

owns


UIAPPLICATION

the app’s DELEGATE

WINDOW

views for 1

VIEW CTL 1 VIEW CTL 2

views for 2

BRING YOUR OWN

DONE!

DONE!

DONE!

BRING YOUR OWN

BRING YOUR OWN

DONE!COMBINE ‘EM

ALL!COMBINE ‘EM

ALL!

owns


A SIMPLE APP · TOOLS DEMO.


Memory management(IMPORTANT BUT BRIEF)


Memory management

No automatic garbage collection! (unlike Java, C#)

Reference counting!

If you do it wrong your app will leak or

crash or

both!!!


CREATED!1

-retain;2!

-release;1!

-release;0!

DEALLOCATED!-


NSArray* a = [[NSArray alloc] init]; // you own it[a retain]; // you own it x2[a release]; // you own it[a release]; // gone!


NSArray* a = [NSArray array]; // what do I have to do here?!?

// the answer: NOTHING! no release, no retain,

// unless you need it PAST this function’s return.


CREATED!1

-autorelease;1

AUTORELEASE POOL

LATER!(release)0!

DEALLOCATED!


THE RULES (1):

every use of:•alloc/init•retain•copy…•new…

must be balanced by a call to either of:•release•autorelease

AND NOTHING ELSE.venerdì 19 novembre 2010

THE RULES (2):

if you want to keep an object you don’t own past the end of the current function, you need to call -retain on it (and -release or -autorelease when done with it).


Goodies you get on iOS + App Store.


BONJOURNETWORK AUTODISCOVERY


GAME CENTERBLUETOOTH + WIFI + ’NET · LEADERBOARDS · ACHIEVEMENTS · INVITES · MATCHMAKING · VOIP


IADINTEGRATED ADVERTISING PLATFORM · NO EXTRA BUREAUCRACY


IN-APP PURCHASEPAYMENT PROCESSING FOR IN-APP FEATURES & CONTENT · NO EXTRA BUREAUCRACY


COUNTRIES SUPPORTED BY APP STOREWOW.

90!venerdì 19 novembre 2010

LOCALIZATION + TOP-TIER UNICODE SUPPORTBUILT-IN TO THE CORE OF THE PLATFORM.


GOOGLE MAPS & GEOLOCALIZATIONNO NEED TO PAY GOOGLE’S APPLICATION €€€


AUDIO AND VIDEO PLAYBACK + ENCODINGON A MOBILE DEVICE! · H.264 + AAC + MP3 + UNCOMPRESSED FORMATS


CORE DATAOBJECT DATABASE · TONS OF FEATURES · OPTIMIZED FOR MOBILE · > 1MLN OBJECT STORES


CORE ANIMATIONUNDERLIES EVERYTHING ONSCREEN · TWEENING · 3D · HIGH-PERFORMANCE · MADE FOR UIS


SECURITYONBOARD AES ACCELERATION · ENCRYPTED STORAGE · API FOR APP USE · REMOTE MANAGEMENT


App Store


WHAT IT IS:

• The only way you can get apps on your iPhone (except development)

• Hosting

• Payment processing

• Sales!


TO PUBLISHYOU NEED:

• Mac + dev tools + test devices

• Developer program account (79€/year)

• Lots of patience

• VAT # + good accountant (Italy)

• A business plan!


YOU CAN PUBLISH: • Most stuff.


YOU CAN’T PUBLISH:

• Porn

• Stuff that misleads

• Stuff that uses Apple trademarks unfairly

• Stuff that breaks privacy laws

• Stuff whose behavior changes after review

• Interpreters (!) (*)

• Betas & Demos


BORDERLINE:

• Satire

• Crashers

• “Lite”

• Big downloaders

• More apply depending on APIs

https://developer.apple.com/appstore/resources/approval/guidelines.html






YOU SET THE PRICE:

• $0.99 to $999.99 (and international equivalents)

• Most apps in the $0.99-$4.99 range

• You get 70%

• Apple gets 30% (and VAT/taxes if applicable)


IT’S A GAMBLE.


iPAD!


TESTDEVICE

DATE PURPOSENOVEMBER 17TH VARIES

IPADTHE NEW HOTNESS


The iPad is another kind of animal altogether.


iPhone

Take it out, use it, back in the pocket.

Small screen means one thing at a time

Mostly used for its connectivity

iPad

Take it out, use it for a longer period of time.

Larger screen means more stuff/more details.

Mostly used for media consumption and productivity

MORE THAN A PHONENOT ENTIRELY

UNLIKE A LAPTOP


Laptop

Traditional mouse/keyboard paradigm.

Chrome around your media

Usually portable

Good text entry

iPad

Multitouch, like on iPhone (and better!)

Just the media

Highly portable

Decent text entry

OLD AND BUSTEDA DIFFERENT THING,

CLEARLY


The iPad is the iPhone, all grown up to be an actual computer.


There’s more space.USE IT.


→


HTTP://WWW.APPLE.COM/IPAD/GUIDED-TOURS/#IBOOKS


http://www.apple.com/ipad/guided-tours/#ibooks

http://www.apple.com/ipad/guided-tours/#ibooks

HTTP://WWW.APPLE.COM/IPAD/GUIDED-TOURS/#PAGES


http://www.apple.com/ipad/guided-tours/#pages

http://www.apple.com/ipad/guided-tours/#pages

HTTP://WWW.YOUTUBE.COM/WATCH?V=GEW68QJ5KXW


http://www.youtube.com/watch?v=gew68Qj5kxw

http://www.youtube.com/watch?v=gew68Qj5kxw

We don’t know what the iPad is…


… because it’s a new kind of computer.


PLAYING MAKE-BELIEVEEXCEPT IT WORKS FOR REAL


THE FUTUREOH MY GOD THE FUTURE


YEAH WE’RE DONE! Questions?


Lecture (November 18th): Basics of iOS Development

Technology

Transcript of Lecture (November 18th): Basics of iOS Development